Golf club shaft having wave shaped reinforced part and making method thereof

Abstract

The present invention relates to a golf club shaft 25B having improved torsion characteristics comprising a base shaft 5 having an internal surface and an external surface, and at least one wave shaped reinforced part 30 on at least one of said surfaces, said wave shaped reinforced part 30 comprising a plurality of reinforcement pieces. The wave shaped reinforced part 30 is located on at least one of the upper portion, midpoint or lower portion. The golf club shafts of the present invention can be made by applying a base section 2B of a prepreg sheet 2A or assembly having a plurality of finger like elements 2 to a portion of a base shaft 5, wrapping the finger like elements 2 around the base shaft 5 to provide a wave shaped reinforced part 30 having a plurality of reinforcement pieces, and curing the shaft having the wave shaped reinforced part 30 thereon to produce a golf club shaft 25B having a wave shaped reinforced part 30.

Description

[0001] This application is a continuation-in-part of Serial No. 29 / 061700, filed October 29, 1996, and Serial No. 08 / 760079, filed December 4, 1996. This application claims the benefit of US Provisional Application No. 60 / 047697, filed May 23,1997. technical field [0002] The present invention relates to a golf club shaft, in particular, to a golf club shaft having a corrugated reinforcement, and to a method of manufacturing the golf club shaft. Background technique [0003] Since the carbon (graphite) shaft is lighter than the conventional steel shaft, the head speed of the golf club increases during the swing, thereby increasing the flight distance of the ball hit by the golf club. However, graphite shafts have a disadvantage in that they have poor torsion characteristics. If the twist characteristics of the club shaft are poor, the midpoint of the ball striking face of the club head generally does not touch the ball during...

AI Technical Summary

Problems solved by technology

Inaccurate ball flight distance when the ball is hit by an area other than the midpoint of the face of the clubhead

[0004] According to the traditional method of improving the torsion characteristics of rods, first, the fiber orientation of the twisted layer (the angle formed by the rod axis and the carbon fiber texture in the prepreg sheet) should be ±45°, and the prepreg sheet is used for rolls. Winding the rod several times; however, the disadvantage of this method is that the flexural strength is significantly reduced and the weight of the rod increases, although the torsional characteristics are improved

[0005] Second, steel or aluminum alloy is installed inside and on top of it, and prepreg sheets are laminated so that the texture organization (grid) of carbon fiber is consistent with the axial direction of the rod; but the use of steel inner tubes increases the weight, so Compromises the lightweight characteristics of carbon rods

[0007] Korean Patent Laid-Open No. 95-23427 describes a method of providing some reinforcing wires in the rod, but this method has the disadvantage of increasing the weight of the rod

[0008] Korean Patent Publication No. 96-1936 describes a method of forming a hexagonal or octagonal hollow portion in a rod, but its manufacturing process is very complicated, although the flight distance is increased

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